Indian Tribes are specifically mentioned in two clauses in the main body and in the 14th Amendment.
Article I, Section 2: This section states that “Representatives and direct Taxes shall be apportioned among the several States ... excluding Indians not taxed.”
This clause reflects the status of Native Americans at the time the Constitution was written, indicating that they were not considered part of the American body politic and were not subject to taxation or representation
Article I, Section 8, Clause 3 (Indian Commerce Clause): This clause grants Congress the power “to regulate Commerce with the Indian Tribes.”
This establishes a significant federal authority over tribal affairs, allowing Congress to enact laws that affect tribal governance and commerce.
Fourteenth Amendment, Section 2: This amendment modifies the earlier clause regarding representation, further clarifying the status of “Indians not taxed” in the apportionment of representatives
Also they are recognized to have “inherent sovereignty”.
Inherent Sovereignty: Native American tribes possess inherent sovereignty, meaning their authority to govern themselves predates the U.S. Constitution. This sovereignty is recognized and affirmed by the Constitution, allowing tribes to maintain their internal governance and legal systems.
They are like any other foreign power in that respect. The United States could make a treaty with Spain and cede territory. The United States could break that treaty. The United States could declare war with Mexico and take the Southwest.